WALL 1310-10
Osteology: Fun with Roadkill
Oct 18 Class Outline
1:30 Introduction to the Osteology Collection
1:35 Classification
bases:
structure
development
biogeography
DNA sequencing
schemes:
Linnean taxonomy
cladistic phylogeny
evolutionary phylogeny
Phylum Chordata
notochord
dorsal hollow nerve cord
pharyngeal gill slits
post-anal tail
ultimobranchial/thyroid gland
Subphylum Vertebrata
vertebral backbone
cephalization with three-region brain
neural crest tissues
semicircular canals
nephritic kidneys
1:40 Practical vertebrate osteological taxonomy
Class Agnatha – jawless fishes; no appendages, no cranium, no
vertebrae (notochord only), single dorsal nostril
Myxini – hagfish
Cephalaspidomorpha/Petromyzontia – lampreys
Class Chondrichthyes – cartilaginous fish; virtually no bone, patent
notochord, oily liver for buoyancy,
horizontal pectoral fins for planning,
heterocercal tail, dorso-ventral flattening
Elasmobranchii – sharks, skates, rays, sawfish; multiple exposed
gill slits, open chondrocranium
Holocephali – ratfish and rabbitfish; enclosed cartilaginous
cranium, gill covers, six dental plates (teeth)
Class Osteichthyes – bony fish; bony skeleton, no notochord in adult;
partial consolidation of vertebrae; bony ribs,
opercula cover gills, swim bladder for buoyancy
Actinopterygii – ray-finned fish; fins supported on delicate bony
rays
Paleonischiformes – sturgeons, paddlefish, bichirs; largely
cartilaginous skeleton
Neopterygii – true bony fish; largely bony skeletons
Chondrostei – gars
Holostei – bowfins
Teleostei – teleost fish
Sarcopterygii – lobe-finned fish; fins supported by multiple basal
and radial bones
Crossopterygii – coelacanth
Dipnoi – lungfish
Class Amphibia – amphibians; first true tetrapods, pentadactylous
(five fingers and toes), ventral lungs, aquatic
larval form, three-chambered heart; no eyelids
Urodela/Caudata – salamanders; short dorsal ribs; no ear hole
Anura/Salientia – frogs and toads; no tail, elongated hind legs,
external eardrum, modified pelvis with urostyle
Mesobatrachia – primitive frogs
Neobatrachia – modern frogs
Apoda – caecilians; legless amphibians
Class Reptilia – reptiles; amnoiotic eggs with leathery case; threechambered heart (except crocodylians); partially
upright posture, consolidated vertebrae, elongated
dorsal ribs
Testudinata/Chelonia – turtles; anapsid skull, ribs form shell with
carapace and plastron, pectoral and pelvic
girdles inside ribcage
Pleurodira – side-necked turtles; neck bends to side to withdraw
head
Cryptodira – bottom-necked turtles; neck bends ventrally to
withdraw head
Squamata – scaly skinned reptiles; diapsid skull, loss of legs in
several groups
Lacertilia – lizards
Squamata – snakes
Amphisbea – amphisbeans
Rhyncocepala/Sphenodonta – tuataras
Crocodylia – crocodiles, alligators, caimans, gavials; leathery skin,
extended maternal care; ventral gastralia; socketted
teeth; complete ribcage; four-chambered hearts;
partially warm- blooded
Class Aves – birds; four-chambered heart, modified diapsid skull with
beak, loss of teeth, calcified amniotic eggs; extended
parental care; hollow bones; feathers, complete
homeothermy (warm-blooded); fused arch-shaped
synsacrum; reduced tail; upright stance, enlarged brain
Paleognathidae – ratite birds; flattened sternum rather than
keel/carina
Neognathidae – carinate birds; prominent keel/carina for flight;
fused clavicles (furculum or wishbone)
Galloanseres – fowl and waterfowl
Neoaves – all other modern bird orders
Class Mammalia – mammals; four-chambered heart, synapsid skull,
complete homeothermy(warm-blooded, extended
care of young, live birth of young (except
monotremes); hair; milk production; upright
stance; enlarged brain
Protheriana – egg-laying mammals; common urogenital/anal
opening (cloaca); lay leathery eggs
Monotremata – platypus and echidnas (spiny anteaters)
Metatheria/Marsupialia – pouched mammals; young born
immature and develop in external pouch
Ameridelphia – New World marsupials – 3 orders
Australidelphia – Australian marsupials – 5 orders
Eutheria – placental mammals: embryos/fetuses develop internally
nourshed by placenta
Xenarthra (S. American origin)
Or. Pilosa – sloths and anteaters
Or. Cingulata – armadillos
Afrotheria (African orgin)
Afroinsectiphila
Or. Macroscelidea – sengi (elephant shrews)
Or. Afroscoricida – golden moles and tenrecs
Or. Tubulidentata – aardvarks
Paenungulata
Or. Proboscidea – elephants
Or. Hyracoidea – hyraxes
Or. Sirenia – manatees and dugongs
Euarchotoglires (N. American/Eurasian origin)
Glires
Or. Lagomorpha – rabbits and pikas
Or. Rodentia – rodents
Euarchonta
Or. Scandentia – tree shrews
Or. Dermoptera – culogos (flying lemurs)
Or. Primates – prosimians, monkeys, apes
Laurasiatheria (N. American/Eurasian origin)
Or. Eulypotyphla – shrews, moles, hedgehogs
Or. Chiroptera – bats
Or. Perrisodactyla – (odd-toed ungulates) horses,
rhinos, tapirs
Or. Cetartidactyla – (even-toed ungulates) cattle, deer, pigs,
antelopes, cameloids, hippos, giraffes,
toothed whales, baleen whales
Or. Pholidota – pangolins (scaly anteaters)
Or. Carnivora – dogs, cats, bears, weasels, raccoons, seals,
sealions, walruses, hyenas, mongooses
2:25 Skeletal Articulation – appendicular skeleton
Chimera/Crytozootic classification